The Horseless Headless Horsemann (HHH) is a boss in boss pack 3 and is the undead form of Silas Mann, is a neutral enemy that appears in Mann Manor and the Carnival of Carnage. In Mann Manor, approximately every 8 minutes, he spawns at the currently contestedcontrol point and hunts down players from both teams. He has a great deal of health, is capable of instantly killing any class with one attack, and will continue to rampage until defeated by the players. In the Carnival of Carnage, he spawns in the bumper car games (except Duck Collector) after a certain amount of time, carrying the Necro Smasher instead of his normal weapon.

The Horseless Headless Horsemann is referred to as "Team Fortress's first boss monster" on the official Scream Fortress Update

The Horseless Headless Horsemann (HHH) is a Halloween boss in boss pack 3, he can be stunned, and he takes a few hits before killing most classes. He makes the same sounds as he does in the regular game, so it may be easy to recognize, HHH can get faster than longer he chases, so outrun him and fast!